Track circuit

Okay kiddo, so you know how trains need to know when it's safe to move and when it's not safe, right? Well, a track circuit helps them do that.

Here's how it works: the train tracks are divided into little sections called "blocks". Each block has its own track circuit. A track circuit is like a little invisible fence that goes around the block.

Now, the train has something called a "shoe" underneath it that touches the tracks. When the train moves into a block, it completes the track circuit by touching the shoe to the track. This tells the train's computer system that the train is in that block, and it won't allow any other trains to enter that block until the original train is clear.

The track circuit also helps with safety. If something goes wrong with the circuit, like a broken wire, it will stop the train from moving into that block so there's no chance of a collision.

So basically, a track circuit is an invisible fence that helps trains know where they are and when it's safe to move. Pretty neat, huh?